How to write an SMS customers actually read

An SMS has almost no room for error. There is no subject line, no image and no second chance. The customer glances at it on their lock screen and decides in a second whether it is worth opening. Here is the structure we use for nearly every message we write.

Give every message one job

Before writing, finish this sentence: “After reading this, the customer should…”. Book a slot. Use a code. Confirm an appointment. If you have two answers, you need two messages, or you need to pick one.

The five-part structure

1. Who it is from. Your brand name first, so the customer knows immediately.
2. Why now. A reason to act today: a deadline, a limited number of slots or a reminder of something they asked for.
3. The specific offer. “15% off all services” beats “great deals”. Numbers are easier to notice than adjectives.
4. One call to action. A short link, a reply keyword or a phone number. Not all three.
5. How to opt out. Short and clear, for example “Reply STOP to opt out”.

Stay inside one SMS part

A standard SMS holds 160 characters. Go over that and the message is split into parts of 153 characters each, and you pay for every part. One character can double your campaign cost.

Watch out for characters that change the encoding. A single emoji, a curly quotation mark or some accented letters switch the whole message to Unicode, which cuts the limit to 70 characters per part. Characters such as €, [ and ~ are allowed but count as two.

We built a free SMS length checker that shows the encoding and the number of parts as you type.

Write like a person

Read the message out loud. If it sounds like a billboard, rewrite it. Short words, everyday language and no capital letters for emphasis. If your customers mostly speak Bahasa Malaysia, write in Bahasa Malaysia. Mixing languages in one message usually reads as careless.

Use personalisation carefully

A first name can lift response, but only if your data is clean. “Hi AISYAH BINTI AHMAD” or “Hi null” does more harm than good. Test your merge fields on a small batch first.

Reminders are different

Transactional messages, such as appointment reminders, are welcome when they are useful. Keep them factual: what, when, where and how to change it. Save the promotions for a separate message.

Test before you send to everyone

• Send the final message to your own phone, and to a colleague on a different network.
• Click every link on a phone, not a laptop.
• Send to a small segment first and compare two versions if your list is large enough.

Good SMS copy is short because it has been edited, not because it was written quickly. Draft long, then cut until only the essentials are left.